Feeding mechanism for sewing machines



J. R. MOFFATT FEEDING MECHANISM FOR SEWING MACHINES lou. s, 1929.

Filed Sept. 26, 1921 2 Sheets-Sheet l Oct. 8, 1929. J. R. MOFFATT FEEDING MECHANISM FOR SEWING MACHINES Filed Sept. 26. 1921 2 Sheets-Sheet 2 Patented Oct. 8, 1929 UNiTED STATES PATENT rori-ICE JAMES R. MOFFATT, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS FEEDING MECHANISM FOR SEWING MACHINES Application filed September 26, 1921.

'I' he invention relates to new and useful improvements in feeding mechanisms for sewing machines, and more particularly to a feeding mechanism which is adapted to be used in a work supporting arm.

An object of the invention is to provide a feeding mechanism for a work supporting arm which is so constructed that the feed dog may be raised and lowered with little or no tilting of the feed dog from front to rear or vice versa.

A further object of the invention is to pro vide a feeding mechanism of the above character wherein the feed bar extends substantially the entire length of the projecting arm and is pivoted at the inner end thereof so that the swinging movements of the feed bar to raise and lower the feed dog will cause said feed dog to move bodily vertically with little or no tilting of the feed dog from front to rear or vice versa.

A still further object of the invention is to provide a feeding mechanism of the above type wherein the feed bar is raised and lowered and ismoved endwise by levers, which levers extend respectively to points within a vertical frame member carrying the work support-ing arm so that eccentric straps may be connected to and operate said respective levers.

i These and other objects will in part be obvious and will in part be hereinafter more fully disclosed. f

In the drawings which show by way of illustration one embodiment of the invention Figure l is a .view in vertical section showing a portion of a sewing 'machine embodyi ng my improvements; n

Fig. 2 is a plan view of the work supporting arm and the upper end of the vertical frame member carrying the arm with the cover plate and throat plates removed to show the parts beneath the same;

Serial No. 503,430.

Fig. 3 is a sectional view on the line 3-3 of Fig.y 2;

Fig. 4 is av sectional view on the line 4-4 of Fig. 2;

Fig. 5 is a sectional View on the line 5-5 of Fig. 2; and

Fig. 6 is a sectional View on the line 66 of Fig. l.

I have shown the invention as applied to a sewing machine of the type disclosed in the patent granted Lansing Onderdonl, December 18, 1906, No. 839,077. Said machine has a frame member extending horizontally and parallel with the overhanging arm. The machine has been illustrated only in part in the drawings, and reference may be made to said patent for a better understanding of the complete machine.

In the present drawings, the horizontally extending member referred to is indicated at l and in said horizontally extending member is an operating shaft 2. Projecting vertically from this horizontally extending frame member l is a vertical frame member 3. The shaft 2 projects into this vertically extending frame member 3. Formed integral with the vertically extending frame member 3 is a work supporting arm l. Said work supporting arm 4 is provided with a bearing bracket 5 at its outer end which is preferably formed integral with the work supporting arm. There is also a bearing bracket member (S at the inner end of this work supporting arm which is detachably secured to the arm by means of screws 7, 7 (see Fig. 6). rIlhe machine as shown,fis a machine of the type wherein the material is fed off from the work supporting arm. The material is held on the work supporting arm by means of a presser foot 8 carried by a presser bar 9. Directly in front of the presser foot in the present embodiment of the invention, is a feeler 9 for overlapping and interfclding ythe edges of a tubular article so that they may be directly beneath the presser foot.

The stitching mechanism preferably consists of a pair of needles 10, l with which cooperates a pair of thread carrying loopers 11, 11. rifhese loopers are carried by a looper support. 12 mounted on the end of a shaft which is mounted in the brackets 5 and 6 so that it may not only oscillate but move endwise in the brackets. The looper supporting; shaft 13 is oscillated and moved endwise by means of lever lei. Said lever 1% cooperates with a crank pin 15 on the operating shaft i2y and at its upper end engages a ball stud 1G carried by the outer end of an'arm 17 (see Fig. which is rigidly clamped to the looper supporting shaft 15. intermediate the ends of the lever le there is a sleeve 18 to which is attached a fulcrum arm which serves as a fulcrum for the lever 14, and this arm so mounted and constructed that the lever can n'iove endwise as well as oscillate, and thus it is that the lever imparts both the loop takingand shedding movements to the loopers, and a needle avoiding` movement. rllhe screw 19 is for the purpose of shifting` the connection of the fulcrum arm with the lever 11i. rlhis looper mechanism for the operatinglever forms no part of the present invention, but is shown7 described and claimed in my co-pending` application iiled of even date herewitln Serial Number 503529.

My improved feeding mechanism consists of a feed bar 20 which extends longitudinally of the work supportingarm Ll, and from a point over the braclret 5 to the inner end of the arm and inner side of bracket 6. rl`his lever 2O carries a feed dog 21 which is secured to the lever by means of a screw 22. he lever at the right hand end thereof is forked as indicated in F 2st 23. rlhe members of the forked end 23 straddle the upper 2 of the bracl'ret 6. (See Fig. 6.) A. pin is carried by the forlred end 23, and said pin intermediate its ends, is slabbed to form a reduced section 9.6. Th upper end 2e of the braclret (S provided with a slot or recess 27 shown in dotted lines in Fig. 1. The reduced section 26 of the pin 25 slides in 'this slot or recess 2'?. A screw 28 passes down throne-h the upper end Qdi of the bracket at left hand side thereof as viewed in Fig. 19 and beyond the range of the sliding movements of the pin The feed bar oscillates this pin for giving to the feed doe,- its rising falling movements. rllhe pin slices in a slot or groove 27 and thus permits t e 'leed bar to move endwise for gir-lino; to tlie feed dog its feeding movements.V t will be noted that the pivotal support for the feed bar 2O is at the extreme right hand end of the worlrsupporting arm Ll, and when the feed bar swings about said pivot to raise and lower the feed dog., the length of the radius on which the feed dog swings is so great,

that the feed dog will practically be raised and lowered bodily without any tilting movements from front to rear or vice versa. rihis is extremely important for it holds the feed dog substantially horizontal throughout its feeding` movements, and thus it is that the feed dog becomes effective to feed the material both in front and in rear of the needles and in the region penetrated by the needles.

The feed bar 2O is raised and lowered by means of av lever 29. VThis lever 29 is fulcruined on a pin 3() mounted in the work supporting arm and held therein by means of a screw 3l (see Fig. The pin 30 has an eccentric section which serves as a fulcrum portion for tl e lever Q9. yllhe screw 31 is also a set screw to hold the pin 30 from turning, and said pin is provided with a slot 33 adapted to receive a s rew driver. By loosening` the set screw 31, the pin 30 may be turned so as to shift the position of the eccentric portion 32 and thus raise or lower the fulcruni point of the lever 29. This serves as a means for raising or lowering the feed dog. rt the inner end of the lever 29 is a pair of linlrs Se, 3 (see Fig. These links 34, 34 are located on opposite sides of the looper supporting shaft 13 and are connected by means of a pivot pin with the lever 'lie links at the upper end thereof are connected to the feed bar 2O by means of a pivot pin The lever 29 extends rearwardly from the pivotal support 30 into the upper end of the vertically disposed frame member 3 and is there pivoted at 3T to an eccentric strap 3S which cooperates with an eccentric on the opeiatinpshaft 2.

llhe feed bar is moved endwise by means of a lever 39. The lever 39 is pivotally supported on a pin el() (see Fig. rlhis pin L10 is carried by the work supporting arm #l and is held in place by a set screw all. Said lever the right hand end thereof projects into the vert ally disposed frame member 3 and is pivoted to an eccentric strap el?) which cooperates wi'h 'the eccentric on the operating shaft 2. The lever entends to the left of the Total pointe() where it is tip-turned and slotted as indicated at The feed bar Q0 the right hand end thereof is 1)rovided with downwardly extending projection A is pivoted at il? to this downwardly eX- tending projection and is also pivoted to a bolt 48 which can be shifted in the slot Ll-l. ils th lever 39 is oscillated, the linlr l@ will he moved endwise and this will move the feed bar endwise. rllhe extent of movement imparted to the linl depends upon the position ofthe bolt -IlS in the slot se. By adjusting:T this bolt, the throw of the fed dog may be readily varied.

rEhe upper portion 0f the worl: supporting arm the vertical frame member are open, and are closed by means of a cover plate 49.

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The throat plate is secured to the worl; supporting arm, and the loopers are enclosed by means of a cap plate 1.

The operation of my device will be obvious from the description which is given above. 'he feed bar is moved endwise by a lever which projects into the vertically disposed frame member and by an eccentric strap located therein, and this endwise movement may be varied by shifting the connection between the lint: and the lever. llhe feed dog is raised and lowered by another lever which extends into the vertically disposed frame member and by an eccentric strap located therein. its said lever oscillates, it 'aises and lowers the outer end of the feed bar and said feed bar swings about a pivot which is disposed sur-h a distance from the feed dog that the feed dog has a movement vertically, with little or no tilting movement, so -that said feed dog remains substantially horizontal throughout its entire movement.

lt is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is-:-

1. 1n a sewing machine, the combination of a vertically extending frame member', a work supporting arm projecting laterally therefrom a feed bar extending lengthwise of said arm, a feed dog carried at the outer end of said feed bar, a stationary support at the inner end of said feed bar, said support having a horizontal slot therein, a pivot pin havthe central part thereof slabbed and adapted to slide baci; and forth in said slot, said feed bar being connected to said pivot pin so that said feed bar may swing on said pivo, pin as an axis, and said pivot pin can more bach and forth with the feed bar, means for swinging the feed bar on its pivot for r. in and lowering the same., and means for moving the feed bar back and forth on said stationary supporti.

2. ln a sewing machine, the combination of a. vt-irtically extending frame member, a work suppe-liturgy," arm pro. Y

an, a feed bar extending lengthwise of said arm, a feed dog carried at the outer end of said bar, means for pivotally and slidably suj'iporting the inner end of said feed bar on a stationary support, means for swinging `aid feed bar on its pivot for raising and owering the feed dog, a lever located in said 'orlr supporting arm between said pivotal .1, `ipport for the feed bar and the feed dog erried by said bar, means for oscillating said ever, a link connected to said lever and to .aid feed bar at a point adjacent said pivosupport for moving said feed bar back and forth on said pivotal support.

t' laterally there-` 3. 11 sewing machine including in combination a vertically extending frame member, a worl: supporting arm projecting laterally therefrom, an operating shaft extending into said frame member, a feed bar extending lengthwise of said arm, a feed dog carried at the outer end of said bar, means for pivotally and slidably supporting the inner end of said feed bar on said work supporting arm whereby said feed bar .is capable of sliding back and forth and wringing about an axis at the inner end thereof, means operated by said sl ft for swinging' the feed bar on its pivot for raising and lowering the feed dog, means operated by said shaft for moving the feed bar back and forth on said pivot, said last-named means including a lever fulcrumcd in said work supporting arm between the ends of said feed bar, means for oscillating said leverv` and a link connecting said lever to said feed bar at a point adjacent the pivotal support for the feed bar.

l. The combination of a vertically extendframe member, a work supporting arm projecting laterally therefrom, an operating shaft extending into said frame member, a d bar extending lengthwise of said arm, a .iced dog carried at the outer end of said bar, means for pivotally and slidably supporting the inner end of said feed bar, means operated by said shaft for swinging the feed bar on its pivot for raising and lowering the feed dog, means operated by said shaft for moving the feed bar back and forth, said means for raising and lowering the feed bar including a lever, a pivot pin located within said work supporting arm and having an eccentric portion on which said lever is fulcrumed, means for holding said pin in adjusted position, links connecting the outer end of the lever to the feed bar, said lever projecting rearwardly into said vertically disposed frame member, and an eccentric strap in said frame men'iber for connecting said operating shaft to said lever.

5, The combination of a vertically extending frame member, a work supporting arm rprojecting laterally therei'from, an operating shaft extending into said frame member, a ed bar extending lengthwise. of said arm, a tre d dog carried at the outer end of said bar, means for pivotally and slidably supporting the inner end of said feed bar, means operated by shaft for swinging the feed bar on its pivot for raising and lowering the feed dog, means operated by said shaft for moving the feed bar back and forth, said pivotal supporting means for the. feed bar including a braclet dl chably connected with said work support arm at the inner end thereof, said bracket having a slot in the upper portion thereof, a pivot pin having the central part thereof slabbed and adapted to slide back and fort-h in said slot, said feed bar having its inner end forked to engage said pivot pin.

non

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6. A sewing machine including n Combination, a Cylindrical Work supporting afm, a feed bar extending lengthwise of said arm, L feed dog eared a+ Jche Outer end of said bal', fol' pvotaly and sldably Suppotng the inne-' end of said feed bar, means, for swinging said feed bar on its pvot for fais- 'ng and lowerno he feed dog, and means fof lnevng he feed bar bach and fo'h n- @lading an ue'ellatng lever located in said Werk Stippel-fing ann/1 and having a sloted end, and a link adjusably Cenneeted to said sleted end of 1he lever and to seid feed bal' af a pon in rem' of the pivotal support at he inner end thereof.

En fesflnony Wheeof, affix my sgnamye.

JAMES R. LOFFATT. 

